deweance



UNITED STATES JOHN.:DEWRANGE,- OF .LAMBETH,

PATENT OFFICE.

OOUN TY OF SURREY, ENGLAND.

ASBESTUS PACKING. v

SPECIFICATION forming part of Letters Patent No. 311,729, dated Pebruary3, 1885.

H l kpplication filed May 31, 1884. (N specimens.)

To all whom it may-concern.-

Be it known that I, JOHN DEWRANCE, of

' Lambeth, in the countyof Surrey, England,

haveinvented certain new and useful Improvenn nts in Asbestus Packing; and I do hereby de lare that the following is a full, clear, and

exact description of the invention, whereby a person skilled in the art to which it pertains can make and use the same.

My invention relates more particularly to asbest-us as prepared for use as a packing for steam-valves and the like.

It consists in covering the fibers of theasbestus with and cementing them together by means ofindia-rubber, or the like article, hardened as by vulcanization.

I am aware that asbestos has been used as a component part in ,a packing formed of lay ers of asbestus and india-rubber; that ashest-us, india-rubber, and sulphur have been thoroughly mixed and incorporated by grinding together, and, also. that india-.rubber and triturated or comminuted asbestos have been kneaded and thoroughly mixed together, whereas t-heprincipal point of my invention is that the separate fibers shall be to a certain extent inclosed by the hardened gum.

In the practice of my invention the fiber of the asbestus is disintegrated in any suitable 'manner common in the arts for putting vegetable'or animal fibers into acondition which render them suitable for working, and foreign subst ances are then preferably removed. The removal of foreign material or corrosive salts is not, however, absolutely necessary; While the fiber is in this loose stateit is mixed with rubber in solution in any proper vehicleas naphthathe said solution containing an amount of sulphurnccessary to Vulcanize the X mixture, and these ingredients are thoroughly mixed together. The naphtha is then thor- 'oughly'evaporated, and the composition is in proper condition to be inserted for a packing in such devices as may be without injury subjected to thenecessary degree of heat to vul-- oanize the rubber. An instance of .such a use of the packing is found in the improved steamvalves as made by me, the packing prior to vulcanization of the cementing material being forced into chambers or grooves between the working parts of the valve, the latter then being heated so as to vulcanize the rubber. The composition of asbestus fiber and gum prior to vulcanization may, afterthe thorough evaporation of the naphtha, be compressedinto any desired shape, and then it is submitted to a suffieient degree of heat to vulcanize the gum, which may be india-rubber, guttapercha, or any like gum, and the hardening may be accomplished by the process of vulcanization or by any equivalent means of hardening such material.

It is to understood that the per cent. of rubber or gum mixed with the asbestus fiber in the making of my improved packing is the least amount that will serve to bind together the fibers ofasbestus, leaving the latter to stangi the mz in burdeu of the wear in its use as a packing, andan essential point in my invention is that the india-rubber or like gum .is deposited in solution on the fibers of asbcsconsists-in incorporating with asbestos fibers in a loose state india-rubber or the like gum and'sulphur or other hardening material in solution, evaporating the vehicle by which the gum is dissolved, and then hardening the mass by subjecting it to heat, all substantially as described.

2. As an improved article of manufacture, apacking for steam-valves and thelike formed of asbestos fiber or equivalent material coated with iu'dia-rubbtr or the like gum in solution, all substantially as described.

3. As an improved article of manufacture, a packing fors'team-valves.or the like formed of asbestos fiber coated w th indie-rubber or the like gum in solution, then compressed to shape and hardened, as by heat, all substantially as described. v

J OHN DEVVRANO'E. \Vitnesses:

EDGAR HAMMOND Minus, GEORGE HENRY WALL,

Both of 158 G1. Dorm St, S. 

